Under the veil of darkness refers to an event or action that is done secretly or covertly during nighttime. Synonyms for this phrase include "in the dead of night," "under the cloak of darkness," "under the shroud of darkness," and "under cover of night." These phrases all imply a certain level of secrecy and hiddenness, as though the action being taken is forbidden or illicit. The use of darkness as a cover can also suggest danger or risk, adding to the tension of the situation. Regardless of the specific phrase used, they all convey the same sense of something happening unseen and unnoticed.